Ethics is concerned with 'right and wrong', although agreeing what is 'right' can be challenging. An understanding of ethics is essential to the delivery of skilled professional care. It is vital that nurses appreciate the value of ethics in their work. Ethics is relevant to clinical, practice-based issues and affects all areas of the professional nursing role. To apply ethics effectively, nurses must develop reasoning skills and understand the concepts and principles that assist ethical analysis. This article, the first in a series of articles relating to ethics and nursing, offers an introduction to ethics, primarily focusing on their application in clinical nursing practice. Throughout the article, the terms 'ethical' and 'moral' are used interchangeably.